Air-bag treatment



Why 13, 1924. 1,494,157

, c. H. DESAUTELS AIR BAG TREATMENT Filed April 17. 1922 INVENTOR county of Hampden an CHARLES H. DIESAUTELS, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO THE FISK RUBBER COMPANY, OF CHICOPEE FALLS, MASSAGHU'SE'I.TS,

EASSACEUSETTS.

A CORPORATION OF v ram-nae 'rnm'rimn'r.

Application filed April 17, 1922'. Serial 1%. 554,088.

To all whom it may concern:

Be it known that I, Cnmmas' H. DESAU- runs, a citizen of the United States of America, residing at S ringfield, in the State of Massachusetts, have invented certain new and useful Improvements in Air-Bag Treatment, of whic the following is a specification.

My present invention relates to the treat 10 ment of articles such, for example, as the vulcanizing bags used in curing cord tire casin with the object of greatly prolong-.

ing t e life of the bags and therefore reducing the cost of, tire manufacture.

The invention will be. described in connection with the accompanying drawings, in which- Fig. 1 is a view of a vulcanizing be showing in adjacent se ents an untreat section, a section having received partial treatment, and a section completely treated; Fi 2 is a transverse section of a bag of whic a part is shown untreated and the rell mainder treated accordin to my invention. In the manufacture o f cord tires it is [cuistoma to vulcanize them while held distende into a rigid mold by an ex ansible annular bag inflated by a fluid un er pres- J sure such as air or water. Each bag is used in the vulcanization of a succession of tire casings, and as the cost of the bag is distributed among all the tires which are cured on it, it is obviously important from a manuing off the outersurface of the bag. This can be accomplished by directing the flame of an acetylene or other torch directly upon the surface, or by other suitable means. This serves to fuse the rubberat the surface ofv the bag, both closing up the-cracks and so disintegrating the outer rubber that it can easily be brushed off. Due to the low heat conductivity of the rubber the fusing effect is confined to a relatively thin layer at the outer surface, the rubber in the body of the bag beingmpractically unaffected by the heat. The dept to which the rubber is fused may be rea ily regulated by the intensity of the heat and the length of its ap lication. After the fusion of the rubber as escribed, and either while it is still hot or after it has been allowed to cool, the disintegrated rubher at the surface of the ha is removed, conveniently by the use of a wire brush. As this leaves a slight coating of rather sticky rubber, theadhesiveness of the surface is preferably destroyed as by dustin thevbag with a substance such as powdered mica'or soapstone. The bag may now be put back into use and put through successive vulcanizing heats until cracks again develop. The renovating process may be repeated until the materia of the ba has become overcured throughout its thic ess, or has deteriorated or been worn down to such an extent that. it cannot withstand the internal pressure, and greatl increases the life of the bag. The cost 0 renovating the bag according to this process is inslgnificant in comparison to the cost of the bag, and the treatment of theba is rapid and under conditions where the epth of treatment can be readily controlled.

In Fig. 1 of the drawing, I have shown an air bag 10 divided into three segments or zones, illustrating diagrammatically the progress of the treatment. In zone 11 are shown by short lines the cracks on the outer surface of the ba The material at the sur- 7 5 facturing cost stand oint to increase to as large extent as ossi Ie the number of vul-- canizing heats w ch a baglwill stand. With certain types of bags, suc for example, as

' the so-cal ed ha which are composed principal y of rub er alone or rubber compounded with an inert filler, one of the chie causes of shortening of the lifeof a bag is the checkin or scaling of its outer surface. After a ag has gone through a 45 number of vulcanizing heats the rubber at its surface becomes over-cured and hard, and cracks develop which at length ow to such an extent as to cause defects in tires vulcanized on the bag. The gum bag is used 9 as an illustration, but other types develop similar troublesand may bev renovated by treatment according to this invention.

1. have found that bags in which these surface defects occur can be renovated and their useful life much increased by bumface is fused an disintegrated by the heating as indicated by stippling in the second zone 12; The third zone 13 represents the bag with the smooth surface imparted by brushing off the disintegrated material on the outer surface. In Fi 2 I have shown the bag in transverse sectlon, the left hand side representing the untreated bag in the cracks condition resulting from its use on a number of heats, and corresponding to zone 11 of Fig. 1; and the right hand side representing the treated bag in a condition corresponding to zone 13.

Having described my invention, I claim:

1. A method of renovating a rubber vulcanizing bag comprising fusing its surface, removing the fused portion, and dusting the surface with a mica-like substance.

2. A method of renovating a rubber vul- 10 canizing bag comprising fusing its surface by the direct application of a' high-tempera ture flame thereto, removing the fused portion, and dusting the surface with a micalike substance.

' 3. A method of renovating a rubber vulcanizing bag comprising fusing its surface and removing the fused portion.

4. A method of renovating a rubber vulcanizing bag comprising fusing its surface by the direct apphcation'of a high-temperature flame thereto and removing the fused portion.

CHARLES H. DESAUTELS. 

